Method for the processing of radiography cardiac images with a view to obtaining a subtracted and registered image

Abstract

In a method for processing radiography cardiac images in order to obtain a subtracted and registered fusion image, at the start of a medical intervention, a radiology image of the heart is obtained by injection of a contrast product into one of the anatomical structures of the heart. Radioscopy images are acquired and are viewed in real time. A subtraction algorithm is implemented. This subtraction algorithm uses the radiology images to make the anatomical structures of the heart visible in the radioscopy images. A registration algorithm is implemented. This algorithm is capable of registering these two images by means of a catheter placed in the coronary sinus. This registration makes it possible to obtain perfect concordance between the two subtracted images.

1 .- 12 . (canceled) 
   
   
       13 . A method for processing cardiac images in which
 at the start of a medical intervention, a contrast medium is injected into an anatomical structure of a patient's heart,   the patient's heart is exposed to radiation produced by a radiography imaging apparatus,   through a detector, a radiology image with a contrast medium representing an internal structure of the heart is obtained,   during the medical intervention, the patient's heart is exposed to radiation produced by the radiography imaging apparatus,   through the detector, a succession of radioscopy images representing an internal structure of the heart is obtained,   the method comprising:   subtracting images between the radiology image with the contrast medium and the radioscopy images;   performing a registration between the radiology image with the contrast medium and the radioscopy images to obtain a fusion image;   synchronizing the fusion image with an electrocardiogram signal; and   displaying the synchronized fusion image on a display screen.   
   
   
       14 . The method of  claim 13 , wherein synchronizing the fusion image further comprises:
 during the acquisition of the radiology image with the contrast medium, synchronizing said radiology image with the electrocardiogram,   during the acquisition of the radioscopy images, synchronizing said radioscopy images with the electrocardiogram.   
   
   
       15 . The method of  claim 13 , wherein subtracting the images further comprises:
 subtracting each pixel gray level value of the radiology image with the contrast medium from a corresponding pixel gray level value in the radioscopy images, the correspondence being determined by a position in the plane (x, y) of the pixels in these images.   
   
   
       16 . The method of  claim 13 , wherein the subtraction is recomputed whenever the imaging apparatus or the patient is in motion. 
   
   
       17 . The method of  claim 13 , wherein registering the radioscopy images with the radiology image further comprises:
 applying an algorithm for detecting a catheter of a coronary sinus to the radioscopy images and to the radiology image with the contrast medium; and   superimposing the catheter of the coronary sinus detected in the radioscopy images and the catheter of the coronary sinus detected in the radiology image with the contrast medium.   
   
   
       18 . The method of  claim 13 , wherein the registration is done by putting into concordance external contours of the anatomical structures in the radioscopy images with external contours of the anatomical structures of the radiology image with the contrast medium. 
   
   
       19 . The method of  claim 13 , wherein the registration is done by achieving the concordance, in the radioscopy images and in the radiology image with the contrast medium, of an artificial object introduced into the heart to identify a motion of the anatomical structure of the heart. 
   
   
       20 . The method of  claim 13 , wherein the anatomical structure into which a contrast medium is injected is determined as a function of the medical intervention to be performed. 
   
   
       21 . The method of  claim 13 , wherein the registration is recomputed or redone manually whenever the imaging system or the patient is in motion. 
   
   
       22 . The method of  claim 13 , further comprising:
 segmenting the radiology image with the contrast medium and the radioscopy images.   
   
   
       23 . The method of  claim 13 , further comprising:
 creating markers in the fusion image at predetermined positions representing an anatomical position or a position of a zone to be processed.